Question

What is the docker command to add or update a published port?

a) docker port add [container ID] [port]
b) docker publish update [container ID] [port]
c) docker expose [container ID] [port]
d) docker run -p [host port]:[container port] [image]

Answer 1

The correct docker command for adding/updating a published port is 'docker run -p [host port]:[container port] [image]' when starting a new container. Existing running containers cannot have their ports updated with a command; they must be recreated with the desired port mappings.

Step-by-step explanation:

The correct docker command to add or update a published port when starting a new container is:

d) docker run -p [host port]:[container port] [image]

This command creates a new container using a specified image and publishes a container's port to the host. The syntax -p is used to map a host port to a container port. It is important to note that once a container is running, you cannot add or update a port using a Docker command. Instead, you would need to stop the container, remove it, and run a new container with the updated port mapping.